PFM Crown Prep in a Digital Workflow: A Practical Guide for Predictable Results

PFM (porcelain-fused-to-metal) crowns still have a place in modern, scan-driven dentistry—especially when you want time-tested strength. The key to predictable outcomes in a digital pipeline is clear margins, adequate reduction, and scan discipline that makes your lab’s job straightforward.

When PFM still makes sense

PFM remains a reliable option for posterior strength and functional durability. In highly esthetic zones you’ll often favor monolithic alternatives (e.g., zirconia or lithium-disilicate), but for many posterior cases PFM is a solid choice—provided the prep allows space for the metal substructure + opaquer + porcelain stack.

Digital-first principles that reduce remakes

• Margin clarity: Choose a shoulder or chamfer that scans cleanly; avoid feather/knife-edge margins (hard for scanners to capture).

• Soft-tissue control: Pack cord (often double-cord) so the margin is visible 360°.

• Dry, clean field: Eliminate blood/saliva/debris on the prep, adjacent contacts, and opposing.

• Scan habits: Capture full arches; keep cheek/tongue/gloves out of view; use a tight interproximal pass; re-localize on a familiar occlusal surface if tracking pauses.

• Verify before you dismiss: Confirm margin readability, interproximal contacts, accurate bite, overall reduction, path of insertion, and shade/photos.

Step-by-step PFM prep in a digital pipeline

1. Provisional plan: Take a pre-op impression/scan for the provisional (most cases benefit).

2. Tooth reduction: Prep with diamonds that create obvious, continuous margins; round internal line angles.

3. Tissue management: Retract (cord) so the entire finish line is visible.

4. Prepare to scan: Clean, dry, and isolate; confirm no cord/blood obscures the margin.

5. Scan: Full arches plus interproximals; maintain moisture control throughout.

6. Evaluate scans: Margin clarity, smooth interproximal data, accurate centric, adequate material space, path of insertion, shade/photos.

7. Submit + provisionalize: Send the case; seat the provisional; schedule delivery per lab turnaround.

Anterior vs posterior: what changes

• Anterior: PFM is less common due to esthetics (metal substructure can influence value/chroma at the margin). Consider whether a monolithic option gives a better result.

• Posterior: Ensure sufficient occlusal/axial reduction for the full PFM stack. Digital workflows often favor shoulder/chamfer margins and clean taper for scan capture and fabrication.

When PFM might not be ideal

• Inadequate reduction (no space for metal + opaquer + porcelain).

• Metal sensitivity/allergy.

• High-visibility esthetic zones where a metal base risks show-through.

A quick lab-friendly QC checklist (before you send)

• Finish line is continuous, visible 360°, and easily scannable.

• Adjacent contacts/opposing are fully captured and smooth (not jagged).

• Bite is accurate bilaterally in centric.

• You’ve included shade (and photos when indicated).

• Reduction and path of insertion are appropriate for PFM.

Tools & supplies that help

• Fine diamond burs for margin/contour

• Zirconia/ceramic adjustment stones & polishers for finishing provisionals/adjacent work

• PMMA discs for provisionals & try-ins

• Wax discs for mockups/occlusion checks

• Zirconia discs for monolithic alternatives in esthetic zones